Patent Literature 1 (hereinafter, referred to as PTL 1) discloses a propulsion device including a hydraulic forward and reverse switching clutch for transmitting a rotation direction of an input shaft to a propeller shaft, the clutch being capable of changing the rotation direction between forward and reverse relative to the input shaft. This propulsion device includes: the input shaft drivably connected to an engine; an output shaft including the propeller shaft; and a hydraulic wet multiplate clutch, positioned between the input shaft and the output shaft, for switching forward and reverse propulsion of the output shaft.